Aims/hypothesis Obesity is a heterogeneous condition comprising both individuals who remain metabolically healthy (MHO) and those who develop metabolic disorders (metabolically unhealthy, MUO). Adipose tissue is also heterogeneous in that its visceral component is more frequently associated with metabolic dysfunction than its subcutaneous component. The development of metabolic disorders is partly mediated by the NLR family pyrin domain containing-3 (NLRP3) inflammasome, which increases the secretion of inflammatory cytokines via activation of caspase-1. We compared the immunological profile and NLRP3 activity in adipose tissue between MUO and MHO individuals. Methods MHO and MUO phenotypes were defined, respectively, as the absence and the presence of the metabolic syndrome. Cellular composition and intrinsic inflammasome activity were investigated by flow cytometry, quantitative RTPCR and tissue culture studies in subcutaneous and visceral adipose tissue from 23 MUO, 21 MHO and nine lean individuals. Results We found significant differences between the three study groups, including an increased secretion of IL-1β, increased expression of IL1B and NLRP3, increased number of adipose tissue macrophages and decreased number of regulatory T cells in the visceral adipose tissue of MUO patients compared with MHO and lean participants. In macrophages derived from visceral adipose tissue, both caspase-1 activity and IL-1β levels were higher in MUO patients than in MHO patients. Furthermore, caspase-1 activity was higher in CD11c+CD206+ adipose tissue macrophages than in CD11c−CD206+ cells. Conclusions/interpretation The MUO phenotype seems to be associated with an increased activation of the NLPR3 inflammasome in macrophages infiltrating visceral adipose tissue, and a less favourable inflammatory profile compared with the MHO phenotype. [less ▲]

AIMS/HYPOTHESIS: The aim of the study was to investigate the use of hyperglycaemic clamp tests to identify individuals who will develop diabetes among insulinoma-associated protein-2 antibody (IA-2A ... [more ▼]

AIMS/HYPOTHESIS: The aim of the study was to investigate the use of hyperglycaemic clamp tests to identify individuals who will develop diabetes among insulinoma-associated protein-2 antibody (IA-2A)-positive first-degree relatives (IA-2A(+) FDRs) of type 1 diabetic patients. METHODS: Hyperglycaemic clamps were performed in 17 non-diabetic IA-2A(+) FDRs aged 14 to 33 years and in 21 matched healthy volunteers (HVs). Insulin and C-peptide responses were measured during the first (5-10 min) and second (120-150 min) release phase, and after glucagon injection (150-160 min). Clamp-induced C-peptide release was compared with C-peptide release during OGTT. RESULTS: Seven (41%) FDRs developed diabetes 3-63 months after their initial clamp test. In all phases they had lower C-peptide responses than non-progressors (p < 0.05) and HVs (p < 0.002). All five FDRs with low first-phase release also had low second-phase release and developed diabetes 3-21 months later. Two of seven FDRs with normal first-phase but low second-phase release developed diabetes after 34 and 63 months, respectively. None of the five FDRs with normal C-peptide responses in all test phases has developed diabetes so far (follow-up 56 to 99 months). OGTT-induced C-peptide release also tended to be lower in progressors than in non-progressors or HVs, but there was less overlap in results between progressors and the other groups using the clamp. CONCLUSIONS/INTERPRETATION: Clamp-derived functional variables stratify risk of diabetes in IA-2A(+) FDRs and may more consistently identify progressors than OGTT-derived variables. A low first-phase C-peptide response specifically predicts impending diabetes while a low second-phase response may reflect an earlier disease stage [less ▲]

The ADA and the EASD recently published a consensus statement for the medical management of hyperglycaemia in patients with type 2 diabetes. The authors advocate initial treatment with metformin ... [more ▼]

The ADA and the EASD recently published a consensus statement for the medical management of hyperglycaemia in patients with type 2 diabetes. The authors advocate initial treatment with metformin monotherapy and lifestyle modification, followed by addition of basal insulin or a sulfonylurea if glycaemic goals are not met (tier 1 recommendations). All other glucose-lowering therapies are relegated to a secondary (tier 2) status and only recommended for selected clinical settings. In our view, this algorithm does not offer physicians and patients the appropriate selection of options to individualise and optimise care with a view to sustained control of blood glucose and reduction both of diabetes complications and cardiovascular risk. This paper critically assesses the basis of the ADA/EASD algorithm and the resulting tiers of treatment options. [less ▲]

IL-1beta and TNF-alpha contribute to pancreatic beta cell death in type 1 diabetes. Both cytokines activate the transcription factor nuclear factor-kappaB (NF-kappaB), but recent observations suggest that NF-kappaB blockade prevents IL-1beta + IFN-gamma- but not TNF-alpha + IFN-gamma-induced beta cell apoptosis. The aim of the present study was to compare the effects of IL-1beta and TNF-alpha on cell death and the pattern of NF-kappaB activation and global gene expression in beta cells. METHODS: Cell viability was measured after exposure to IL-1beta or to TNF-alpha alone or in combination with IFN-gamma, and blockade of NF-kappaB activation or protein synthesis. INS-1E cells exposed to IL-1beta or TNF-alpha in time course experiments were used for IkappaB kinase (IKK) activation assay, detection of p65 NF-kappaB by immunocytochemistry, real-time RT-PCR and microarray analysis. RESULTS: Blocking NF-kappaB activation protected beta cells against IL-1beta + IFNgamma- or TNFalpha + IFNgamma-induced apoptosis. Blocking de novo protein synthesis did not increase TNF-alpha- or IL-1beta-induced beta cell death, in line with the observations that cytokines induced the expression of the anti-apoptotic genes A20, Iap-2 and Xiap to a similar extent. Microarray analysis of INS-1E cells treated with IL-1beta or TNF-alpha showed similar patterns of gene expression. IL-1beta, however, induced a higher rate of expression of NF-kappaB target genes putatively involved in beta cell dysfunction and death and a stronger activation of the IKK complex, leading to an earlier translocation of NF-kappaB to the nucleus. CONCLUSIONS/INTERPRETATION: NF-kappaB activation in beta cells has a pro-apoptotic role following exposure not only to IL-1beta but also to TNF-alpha. The more marked beta cell death induced by IL-1beta is explained at least in part by higher intensity NF-kappaB activation, leading to increased transcription of key target genes. [less ▲]